The use of electro-dynamic loudspeakers or earpiece units in apparatus is common. Most electronic devices contain an electro dynamic loudspeaker or transducer configured to convert electrical signals into acoustic waves to be output and heard by the user of the apparatus. For example mobile or similar telephones can contain an integrated transducer sometimes called an integrated hands free (IHF) transducer configured to operate as an earpiece for speech and also as a loudspeaker for hands free and audio signal playback.
Furthermore it has been suggested that electro-dynamic loudspeakers or earpiece units in apparatus can be replaced by generating the acoustic waves using the display. In such suggestions the display is moved or vibrated by actuators or transducers coupled to the display.